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Number triangle binomial(n+3k,4k).
4

%I #3 Mar 30 2012 18:59:08

%S 1,1,1,1,5,1,1,15,9,1,1,35,45,13,1,1,70,165,91,17,1,1,126,495,455,153,

%T 21,1,1,210,1287,1820,969,231,25,1,1,330,3003,6188,4845,1771,325,29,1,

%U 1,495,6435,18564,20349,10626,2925,435,33,1,1,715,12870,50388,74613,53130

%N Number triangle binomial(n+3k,4k).

%C Riordan array (1/(1-x), x/(1-x)^4). Rows sums are A055988. Diagonal sums are A109961. Inverse array is A109962.

%F Number triangle T(n, k)=binomial(n+3k, 4k)

%e Rows begin

%e 1;

%e 1,1;

%e 1,5,1;

%e 1,15,9,1;

%e 1,35,45,13,1;

%e 1,70,165,91,17,1;

%K easy,nonn,tabl

%O 0,5

%A _Paul Barry_, Jul 06 2005